NPB 140 × 70

I-beam — 12.89 kg per metre, 16.4 cm² cross-sectional area. IS 808 Table 3 - Narrow Parallel Flange Beams.

zyB 73D 140T 6.9R1 7t 4.7
Mass per metre
12.89kg/m
Sectional area
16.4cm²
Depth
140mm
Width
73mm

Narrow Parallel Flange Beams (NPB). Reproduced as printed in IS 808 Table 3 - Narrow Parallel Flange Beams.

NPB 140 × 70 section properties

As printed in IS 808 Table 3 - Narrow Parallel Flange Beams. 140 mm deep, 73 mm wide. Units are shown on every row, because the two standards on this site use different ones for the radius of gyration.

Dimensions

Depth of section D 140 mm
Width of flange B 73 mm
Thickness of web t 4.7 mm
Thickness of flange T 6.9 mm
Flange slope 90 °
Root radius R1 7 mm
Toe radius R2 0 mm

Mass and area

Mass per metre M 12.89 kg/m
Sectional area A 16.4 cm²

Major axis (z-z)

Second moment of area Izz 541 cm⁴
Radius of gyration rzz 57.4 mm
Elastic section modulus Zzz 77.3 cm³
Plastic section modulus Zpz 88.3 cm³

Minor axis (y-y)

Second moment of area Iyy 44.9 cm⁴
Radius of gyration ryy 16.5 mm
Elastic section modulus Zyy 12.3 cm³
Plastic section modulus Zpy 19.2 cm³

Torsion and warping

Torsion constant (St Venant) It 2.4 cm⁴
Warping constant Iw 1,980 cm⁶

What a length of NPB 140 × 70 weighs

Total weight is the mass per metre multiplied by the length and the number of pieces. Ten pieces of NPB 140 × 70 at six metres each is 12.89 × 6 × 10 = 773 kg. There is nothing else to it — the standard publishes the mass, so no one needs to compute it from the area.

You can check that mass against the area on this page: 16.4 cm² of steel at 7 850 kg/m³ is 12.87 kg/m. Every row in this dataset was checked that way, which is how the contradictions flagged on some of these pages were found.

Work it out for your own lengths and quantities →

Common questions about NPB 140 × 70

What is the weight of NPB 140 × 70 per metre?

IS 808 : 2021 gives NPB 140 × 70 a mass of 12.89 kg per metre. Its printed cross-sectional area of 16.4 cm² agrees: 16.4 cm² of steel at 7 850 kg/m³ works out at 12.87 kg per metre.

How much does a 6 m length of NPB 140 × 70 weigh?

77.34 kg. Mass per metre times length: 12.89 × 6. Ten such pieces come to 773 kg.

What are the dimensions of NPB 140 × 70?

140 mm deep and 73 mm wide, with a 4.7 mm web and 6.9 mm flanges.

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Where these figures come from. IS 808 Table 3 - Narrow Parallel Flange Beams Section properties are facts published in the standards, and they are reproduced here as printed. Where a standard contradicts itself, both of its figures are shown and neither is corrected.

What is ours. The selection and arrangement of these tables, the checks run against them, and the findings those checks produced — which rows disagree with themselves, which figures were superseded by amendment, and which could not be read — are QuickBOQ’s work, and so is this wording. Quote the numbers freely; they belong to everyone. Copying the compilation and the commentary is a different thing, and we would rather you linked to it.